ABOARD THE USS GEORGE WASHINGTON, Persian Gulf, Feb. 11Lt. Cmdr. Nick Mongillo, who flies an F/A-18 fighter jet for the U.S. Navy, remembers watching enviously as Air Force colleagues captured the headlines during the 1991 Persian Gulf War, dropping "smart" bombs down chimneys. All Mongillo could drop then were conventional bombs, without advanced technology to guide them to targets.

Now things are different. As the United States prepares for possible strikes against Iraq, Navy and Marine Corps pilots are set to fly the majority of missions in an operation code-named "Desert Thunder" that will hinge, by all accounts, on downpours of precision munitions.

Two factors explain the Navy's prominence this time. First, it has improved its weapons and cockpit-targeting systems substantially since the Gulf War, making wide use of laser guidance technology. And second, the Air Force has been handicapped by Saudi Arabia's resistance to letting U.S. land-based aircraft launch strike missions from its territory.

At the center of any U.S. air assault on Iraq would be the F/A-18 and F-14 fighter jets on this aircraft carrier and another, the USS Independence, along with about 250 Tomahawk cruise missiles spread among eight other ships.

Their targets, in the words today of Marine Corps Gen. Anthony Zinni, the commander of all U.S. forces in the Middle East, would be "the things that obviously allow [Iraqi leader Saddam Hussein] to stay in power, threaten his neighbors, threaten the use of weapons of mass destruction." These would be things like sites for producing or storing chemical or biological weapons, military command bunkers, communication networks and special Republican Guard units that provide security for the Iraqi leadership.

Zinni said his forces should be ready to strike "within a week or so." He added: "We're ready now, but there's a few more pieces to put in," referring to deployments of several dozen more aircraft, 2,000 Marines and up to 3,000 Army troops.

He said his biggest remaining worry is whether he and his planners have taken into account "every possible reaction" that Iraq could make to an airstrike. In this regard, he remarked, he would welcome contributions from allies of detection and decontamination equipment to guard Kuwait against Iraqi chemical attack. The United States has promised to send more gas masks to the Kuwaitis.

To reduce the risk of killing innocent Iraqis, and to pulverize some of Iraq's best-protected and most-hardened facilities, defense officials have indicated the airstrikes would rely largely on precision-guided munitions. These weapons feature infrared seekers or TV guidance systems that enable them to be steered to a target.

The Navy had relatively few of these at the time of the Gulf War but has stocked up on smart bombs since -- including 1,100-pound Walleyes, 1,400-pound SLAMS and 2,000-pound GBU-24s. The two carriers in the gulf have more smart weapons between them than did the six carriers used in the 1991 war, according to Navy officials.

"We can go after smaller targets now, pinpointed areas, instead of the broad areas we went after before," Mongillo said. "The 1991 war was an Air Force show because they had more planes in-theater and because they were the PGM [precision-guided munitions] shooters. This time, we have more confidence in our equipment and tactics."

Not only have the Navy's bombs and missiles been improved, but its planes now carry more advanced targeting capability as well -- especially the F-14, whose role in 1991 was limited to air-to-air combat. Now it can deliver smart bombs, too, using a laser-guidance system known as Lantirn.

For all their upgrading, though, Navy strike aircraft still have limitations in range and bomb weight that make them poor substitutes for bigger Air Force planes. The Navy also has nothing to match the radar-evading capability of the Air Force's F-117 stealth jet or the payloads of the B-52 bomber, both of which would perform critical missions in any attack on Iraq.

As the prospect of fighting nears, the pace of flight operations has intensified on this nuclear-powered warship, which was visited today by Defense Secretary William S. Cohen. Instead of 30 or so flight hours a month, some pilots are spending as many as 40 in the air.

But many pilots have done gulf duty before and know the drill. "You'll find the majority of the tactical air crews pretty familiar with the situation," said Lt. Cmdr. Guy Maiden, an F-14 pilot who is on his third trip to the gulf.

So common have these gulf deployments become that Navy pilots routinely train under conditions closely resembling those here. "We practice inside limited sea space and air space and for scenarios that look a lot like what we're facing now," said Lt. Cmdr. Peter McVety, another F/A-18 pilot.

Here, their daily patrols take them over southern Iraq, enforcing a ban imposed on Iraqi military flights after the gulf war. "They're over Iraq every day, and they have an ample opportunity to take a solid look at the terrain and any potential targets that might be available," said Vice Adm. Thomas Fargo, commander of the U.S. 5th Fleet, who has responsibility for the more than 30 U.S. warships now parked in the gulf.

He said that Iraq has been seen dispersing some of its armored forces, evidently to make them harder to hit from the air. The Iraqis also are shifting their Soviet-made surface-to-air missile launchers, a common tactic to elude U.S. detection.

In recounting the evolution of their aviation force since the gulf war, Navy officials remarked on efforts to coordinate better with Air Force operations in places like the Persian Gulf, where both services could have lots of aircraft in the air at the same time.

During the Gulf War, communications between the two services were poor. The "air tasking order," which assigns daily flight missions, had to be flown out to carriers from command headquarters in Saudi Arabia, causing delays and confusion. Now, such orders are transmitted instantaneously by computer between Air Force and Navy units.